Cold Case — Julia Platt Leonard

When 13-year-old Oz Keillor finds a dead body in his family restaurant, he is soon caught up in a mystery where the stakes are high. His older brother is the prime suspect, and Oz quickly finds out that the murder may be tied to the death of their father years earlier, who was accused of selling nuclear secrets to rouge governments.

With the fate of his family in balance, it's up to Oz to try and crack the case, with the help of his best friend, Rusty. It's a quest that has more twists and turns than the dusty roads of New Mexico--with the answer being closer to home than Oz ever could have imagined.